System of processing lint



Patented Feb. Z4, 1942 SYSTEM OF PROCESSING LINT Andrew K. Schwartz, Eugene Bradshaw, and Fredy J. Walker, Houston, Tex., assignors to South Texas Cotton Oil Houston, Tex.

Company, Incorporated,

lApplication December 12, 1938, Serial No. 245,112 2 claims. y (ci. 1a-72) This invention relates to new and useful improvements in systems of processing lint.

The usual procedure of producing clean lint commences with cleaning ofthe cotton seed. After the seed has been cleaned as thoroughly as the machine or apparatus used will permit, it is conveyed to the linters wherein a second cleanhull pepper, dust, whole seed, hulls and shale iny termingled with the same. i i

ing 'operation in the form of moting takes place.

The step` of air separation is incidental to the transfer of the lint from the linters to the condenser or through the lint flue system. When the latter is used, an attempt to clean the lint through the adaptation of a beater or agitator is,

made. The lint is `beaten or agitated above a perforated metallic plate or screen, the perforations of which are of sufficient size to accommodate dust and hull pepper but prevents the removal of the larger trash. The amount of ex' traneous or `foreign matter, in the form of hull pepper or dirt, removed from the lint in this type of apparatus is limited by the loss of lint during the beating operation, which lint is unrecoverable in thisy process and the kind of foreign matter removed is limited to that appearing in a state of subdivision small enough Vto pass through the relatively fine perforations.

It is therefore, one object of'the invention to provide an improved method or system of treating or cleaning lint to produce a cleaner and higher grade lint than has been heretofore possible and to remove some of the limitations of lint cut,` thereby recovering a greater quantity from a given amount of seed.

Another object of the invention is to provide an improved system of processing lint wherein the entire amount of lint cut by thecotton linter, including motes, or any portion of the cut desired, may be incorporated in the production of clean lint, whereby the production and handling of motes asa separate and lower grade commodity is eliminated.

An important object of the invention is to provide an improved system of processing lin't whereby the lint may be classified so that any desired vgrade or combination of grades may be produced,` depending upon market conditions and the particular use to which the lintis to be put. A further object of the invention is to provide lan improved system of processing lint wherein the entire cleaning operation is performed by a single unitary mechanical apparatus irrespective of previouscleaning, moting, gradingor separating operations, the entire cleaning operation beingv accomplished by a process of agitation, screening, and air separation which removes the A particular object of the invention is to provide a system of processing lint whereby an ex ceptionally high quality of lint is produced independent of the mechanical condition of the apparatus and the skill with which said apparatus is operated, whereby the human element is eliminated or reduced to a minimum and the necessity or desirability of maintaining the apparatus in excellent mechanical condition is obviated.

Still another object of the invention is to provide an improved system of processing lint -wherein the amount of lint produced from a given amount of cotton seed is unlimited by the cleanliness of the seed or lby the cleanliness of the lint as cut from the seed, the processing of the lint producing clean lintfrom substantially totally delinted seed, said processing also removing the foreign matter carried by said lint.

A further object of the invention is to create a cleaning system which is capable of removing the type of impurities now eliminated by moting,

thereby creating a new linting conditionwhich allows for lower brush speeds, which in turn results in a saving of power` both in the linter and Y in the lint ue system.

The system may be carried out by any suit' -able means, devices or apparatuses; however, we

have shown in the accompanying drawing, a diagrammatical illustration of apparatus for performing the system of processing, which is described Vin the following specication and to which reference is made herein.

The system of processing lintV includesconveying the cotton lint and motes by any suitable means such as, a suction duct or conduit, from a cyclone (not shown) to the upper end of a separating, agi'tating or beating apparatus lll. The air carried by the lint and motes is removed therefrom by the cyclone (not shown), whereby no separation in the form of moting or delinting is necessarily preformed prior to the introduction of the lint into the apparatus lil. Consequently, the lint, in addition to the motes, will contain a large quantity' of extraneous or foreign matter in the form of whole seed, dust, hulls, hull pepper and shale, which matter must be separated or cleaned from the lint.

The lint is first introduced into an agitator or beater Il for the purpose of removing a portion of the dust and hull pepper therefrom so that the lint may be cleaned more thoroughly and rapidly. This nrst step of introducing the lint into an agitator or beater is optional with the operator and it has been found that the system will work equally as well without this first step. The agitator is shown as a horizontal screw-conveyor 'of the type known as a. cut flight conveyor and spiraled convolutions but may be in any desired form. The screen' A may be constructed' of. anyy suitable material such as, hardware cloth, anda mesh of one-eighth of an inch hasV givenV satisfactory results. The size of the perforations is sufficient to accommodate or permit the passage therethrough of the dust and hull pepper,

but is insuiiicient to permit the" passage of thelarger foreign or extraneous matter. The lint will be tumbled and beaten by the agitator II against the fine mesh screen, whereby themajority of the dust and hull' pepper will fall or be sifted through the perfor-ationsof` said screen.

This line extraneous. matter will have particles of'lint mixed therewith and themixturewill be caught and carried offby a screw-conveyor or similar means I2 in a direction opposite to the direction of travelof the agitator I i. It is noted thatv the conveyor I 2' is-provided with a solid bottom |12 so that no shifting or separation takes place therealong, and that, any means of conveyance might be utilized. The sifted matter is reintroduced into` the apparatus I t as will be hereinafter fully explained. The lint together with the extraneous matter which is too large to pass through the screen A will travel forwardly to the end of the agitator Hf from which it will fall into a second agitator or beater I3. It is also noted that this: netrash is removed in order that the load on the lower agitators will be reduced, whereby it is possible to produce a cleaner lint.

This second agitator includes a cut flight conveyor, similar to the first one, mounted above a screen or perforate plate B which forms a perforated trough or bottom'- for saidA conveyor to work in. The mesh of the screen B is of sufficient size to permit the passage'therethrough on the large form of foreign matter encountered. A mesh of one-half an inch has been found satisfactory. The lint is-tumbled and beaten against the screenr B, whereby some of the lint is separated from the extraneous or foreign matter and is mattedor balled tov a certain extent. 'I'he greater part of the extraneous matter together with a part of the lint will be' sifted through the perforations of the screen B so-that` it may be carried oli by'a screw-conveyor It, havingI av solid bottom It', or by other suitable means. This sifted matter is also returnedto the apparatus I- as will be hereinafter explained.

The matted or balled lint and the unscreened foreign matter is dropped into al third' agitator or beater 5', identical to the agita-tor i3' and havingy the same type ofscrew-conveyor and bottom screen B. The agitator I5 forms a continuation ofv theagitator I3 and merely continues the beating7 or tumbling action of the same, whereby a further separation or screening process is performed. A screw-conveyor or other suitable means It, having a-v solid bottom It', is disposed beneath` the third agitator so as to catch and carry away the matter sifted through the screenA B. It' is'- pointed out' that substantially all of the foreign matter and some of the lint vvill` pass through the perforations of the screen, whereby the matted lint remaining thereabove will be substantially free from said foreign matter when it reaches the far end of the agitator I5.

The substantially clean lint will be discharged from the far end of the agitator into a duct or conduit Il having an air stream or blast passing upwardly therethrough. The velocity of the air stream may be regulated so that it will have sufiicient force to pick up the clean lint but insufficient force to pick up any of the heavy foreign matter that may be discharged into the duct I'I. This foreign matter will be carried away by a separate duct or may be allowed to fall to the floor as desired; It is pointed out that a large quantity of lint will be separated from the foreign matter during the tumbling or beating actionof the agitator i5 so that the clean lint may be carried upwardly by the air stream to a cyclone I8 where the air will be removed o1' separated fromv said lint.

It is noted that the rate of passage or travel of the lint over each screen orl perforate plate may be regulatedv by the number of prongs or paddles carried by each cut flight conveyor and the pitch or inclination of the same and the speed of rotation thereof. Obviously, a few paddles or prongs having only a small degree of pitch or inclination will reduce the rate of passage or travel of the lint and will increase the amount of beating or tumbling by the agitator. Thus, the amount ofbeating or tumbling not only controls the passage of the lint'- over and through the screen' but. also controls the type and amount of air currents induced' thereby.

The sifted foreign matter and lint is discharged from the conveyors I4 and It into a fourth agitator or beater IQ mounted above a screen D'. A ve-sixteenths of an inch mesh screen has been found tol be satisfactoryl Here, the beating or tumbling action is repeated with the foreign matter and part of the lint being sifted through the screen and the clean lint being discharged into the duct Il. The sifted lint and foreign matter is received' and discharged by a solid bottom conveyor 2li into a fifth agitator or beater 2|, identical to the fourth agitator. The clean lint is conveyed to the duct I'I, While the foreign matter and dirty lint is caught by a solid bottom conveyor 22V which discharges the mixture into a sixth agitator 23 having a screen C. A mesh of one-fourth of an inch has given satisfactory results. The clean, matted lint discharged from the agitator 23 is conveyed by suitable means to a duct 2-1', similar to the duct Il, having an air stream passing upwardly therethrough, whereby said lint is picked up vand reintroduced into the fourth agitator I9'. The-lint and extraneous matter is dischargedy from the screw-conveyor I'- into a, suitable conduit 25 where it is picked up by the conveyor Iii andl discharged into the agitator I9. Thus, the lint from the sixth agitating stage is mixed with the discharge of the second conveyor and the same is recleaned by further tumbling or beating. It is noted that either, or both, of these steps are optional and may be eliminated, if desired.

A solid bottom screw-conveyor 26 receives the sifted lint and foreign matter and discharges the same into the seventh agitator 21 having its foraminous bottom formed by a screen E. A mesh of one thirty-second of an inch has been found to be satisfactory. The line dust and hull pepper discharged from the screw-conveyor l2v is reintroduced into the apparatus at this point where charged from the' conveyor x2t. Obviously, only the rfinest particles of the extraneous matter will be sifted through the exceptionally ne screen E, and these impurities will be in the form of dust and hull pepper. The reason Lfor returning this line extraneous matter to the apparatus` is to remove the lint mixed therewith. It is pointed out thatv very little lint `will pass through the screen E, and that, thissifted matter may be disposed of by a screw-conveyor 28 or in any other convenient way.

The larger extraneous or foreign matter and the lint is dischargedfrom the agitator 21 into an eighth agitator 29 having its perforated bottom or trough formed by the screen C. The matted lint is discharged into the duct 24, whereby the lint is picked up by the air stream therein and the heavy extraneousmatter is drop-` ped to the floor. The unmatted lint and foreign matter is shifted through the screen C and is carried by a conveyor 30 `to a ninth `agitator 3|,

identical to theragitator 29 and also having its bottom or trough formed by the screen C. The

matted lint is discharged from said agitator into particular use for which the lint is furnished. The grades of lint produced depend upon the number of agitators employed and the amount of blending of the different grades.

After'the cyclone I8 has removed or separated the air'from the cleaned lint, the latter isv conveyed to a mechanical blender 4|, or other suitable means, -wherein said lint is combined in a uniform mixture composed of fractions having different colors and staples. It is' well known that the color of the lint changes with the length of the duct 24, while the lint and the foreign matter sifted through the screen is conducted by a screw-conveyor 32 to a tenth agitator *33 which is similar to the agitators 29 and 3|. The only difference between the three agitators'is thatfthe number of paddles or prongs on the cut flight conveyors and the inclinationor pitch of the same is adjustable so as to accommodate the decreasing volume of lint. This increase in number and pitch is desirable because less lint is handled by the lower stages, as has been heretofore set forth, and

the staple, and that the short staple close to the seed is naturally darker in color than the longer staple which might be still adhering to the seed.

The recombining of the lint may be accomplished Y by passing a portion or all of the lint to thei l accompanying drawing. v

This system of processing lint is based upon `the idea of utilizing a single unitary apparatus which is capable of performing the entire cleanit` is not necessary to beat or tumble said lint i for an equal period' of time.

Since the remaining beaters or agitators 35,-31 and 39 and solid bottom screw-conveyors 34, 36,

38 and 40, as shown in the accompanying diagrammatical View of the apparatus, are identical to the upper agitators 29, 3| and 33 and the conveyors 28, 3|) and 32, it is thought unnecessary to set forth the same in detail. It is manifest that more or less agitators might be utilized in carrying out the invention according to the condition of lthe lint and the amount of extraneous or foreign matter `mixed therewith.v All of these agitators may .be connected to the duct 24, whereby the lint produced or recovered by said agitators may be re-introduced into the fourth ing `operation independent and irrespective of what precedes its performance in the form of seed cleaning, moting or other attempt at grading or separation. This apparatus accomplishes the desired result by a process of beating, agitation and air separation, whereby the extraneous or foreign matter vmixed with the lint is removed. It is noted that highly undesirable shale, whole seed, largeparticles of hull, leaf and stem trash are substantially removed by this system, which removal has heretoforel been unheard of and thought to be impossible.

The system has its foundation in three principles, namely, agitation or beating of the lint over a screen of desirable mesh, air separation and the regulation of or controlled agitation. The

beating or agitation of the lint, or the major portionY thereof, is performed above and in conjunction with screens or perforate plates having perforations of sufficient size to permit the passage therethrough of the large type of foreign or extraneous matter mixed with the lint. At the same time the separation of the lint from these impurities andthe retention ofthe lint by the agitator I9 or at any other desirable point for f the purpose of blending or recleaning. `It is pointed out that this re-introduction of the lint from the lower agitators may be varied or entirely eliminated, if desired.

The large extraneous matter such as, shale, hulls and seed will pass entirely through the apparatus and will finally be received by the screwconveyor 40 from which the same will be readily discharged and disposed of. It has been stated hereinbefore that the lint recovered or retained by the third, vfourth and fifth agitators I5, I9 and 2|, respectively, is discharged into the duct I'I, whereby the lint is picked up by the air stream therein and the heavy extraneous matter is permitted to fall to the floor or is disposed of otherscreens depends upon the matting effect of said lintrwhich occurs during the agitation thereof land also partially, but not necessarily, upony a diminution of the mesh of the screens as the agitation progresses.

As the tumbled lint is discharged from the end ofthe agitators, it is picked up by an air stream which has been regulated so that its velocity will be suiiicient to raise the lint but will be insumcient to lift the heavy impurities that may be present, as is clearly set out hereinbefore. The amount of agitation or beating and the quantity of lint passing through each screen bears a denite relationship to the rate of passage or travel of `said lint over each screen, and therefore, to the quantity of lint retained by said screen. As has been heretofore stated, thisrelationship may be varied and controlled by the adjustment of the paddles or prongs of each cut-flight conveyor or the speed of rotation thereof, whereby the `passage of the lint above and througheach screen is determined both by the mechanical setting ofi said paddles or prong-sand the; type of air currentsl induced thereby'.

In using this system of processing lint, it has been found to have certain advantages over the systems and apparatuses now in use. In the first place, there is a. saving of power as compared with the. standard lintl flue. systems in that the transmission of the lint from the linter may be accomplished. by the use of afan andacyclone, thereby eliminating the, usual condenser and its. recognized resistance. The system is so efcient that it isv no longer necessary to perform theV usual separation step,l called moting and if desired all of the motes produced byl the linter may be combined with the lint, thereby eliminating a secondary product and the necessity for using mote beating machines. Another advantage is that the recovery may be graded and classred according to staple. The lint discharged from the various agitators maybe combined' in any conceivable combination toproduce lintof predetermined grade or multiple of grades. This grading of the lint may be carried to such an extent as to produce the equivalent of rst cut.

lint with the remaining portion equaling second cut lint, thereby making it possible to eliminate second cut linters. With this type of system it has been found that the necessity for moting in the linter can be eliminated. In the usual cotton linter the saws are turned at a high speed so that motes are thrown clear of the lint and, of course, by this high speed some of the lint is also thrown oi of the saws and is carried along with the motes, whereby the lint carried by the motes is lost. The motes, together with the lint, is carried into this system, thereby eliminating the moting in the linter. It is sometimes desirable to. cut closer tothe seeds and with this type of system it is possible to place more saws in the linter and also to place them closer together, because this system receives the cut seeds as well as the lint.

A survey of the present production or recovery of lint by other methods indicates that by using this new system, it is possible to produce a lint, either in part or by combining all of the lint produced, having a higher degree of purity. For example, it is possible to produce second cut lint with as high a cellulose content as rst cut lint or cotton, while the combination of all the fractions of lint recovered by this system shows a higher cellulose content` than exhibited by other methods or processes now in use. Thus, it is possible to produce a greater yield of lint having a higher quality than has heretoforel been possible.: It. is. noted that. an'A agitator or beater, having aA fine;v mesh screen bottom, may bef installed in theapparatus atany stage of theproc.- essing;` of the lint for thezpurpose ofv removing a largepercentage'- of4 the fine-dust and hull pepper, thereby lightening, the load upon the apparatus. However, this removal of the ne extraneous matter is optional. and may be eliminatedJf de.- sired. Another advantageof the system is that due tothe high efficiency of the cleaning operation, a large. quantity of clean lint may be produced from a unit weight of seed than. withv existing systems. Manifestly, this system 0fprocessing lint may be accomplished by any suitable means'and is not limited tothe apparatus set out hereinbefore.

What we claim and desire to secure by Letters Patent is:

ll. The system of processing cotton lint which includes, successive agitating and tumbling steps over foraminous surfaces, whereby extraneous matter and shorter cotton lint are sifted out and the longer lintv is retained, returning` the extraneous` matter and shorter lint to the agitating and tumbling steps for the purpose of re-cleaning the same, discharging the clean lint into a stream` of air of such force sol as to pick up and convey the clean lint but insucient to pick up heavier foreign matter and then. re-introducing the clean lint back into the system for further cleaning and also blending to combine the same in a uniform mixture.

2. The system of processing cotton lint of the type wherein the lint and extraneous matter are not ground, the improvement which includes conducting the lint and extraneous matter through successive agitating, tumbling and sifting steps, whereby progressively smaller particles of extraneous matter with shorter lintr are separated at each successive step from thelint being cleaned, discharging the cleaned lint into an air stream from said steps and carrying it offv therefrom, separating the cleaned lint from the air stream, continuing processing of the shorter lint and extraneous matter sifted from the preceding steps through additional agitating, tumbling and sifting steps, discharging and carrying off clean lint from the last-named steps by means of an air stream, and combining the said last-named clean lint with the clean lint from the rstnamed steps.

ANDREW K. SCHWARTZ. EUGENE BRADSHAW. FRED J. WALKER. 

